Gas operated stapler



1, 1962 J. A. KHAN I 3,049,712

GAS OPERATED STAPLER Filed April 7, 1961 United States Patent 3,049,712GAS OPERATED STAPLER Joseph A. Khan, Asbury Park, NJ. Filed Apr. 7,1961, Ser. No. 101,509 Claims. (Cl. 1--44.4)

This invention relates to a stapler powered by compressed gas. Presentlyavailable pneumatic powered staplers offer actuating ease, that is alight trigger pull to actuate, but they also require the added expenseand inconvenience of compressors and related equipment. Spring drivenstaplers ofler simplicity and portability, but a considerable force isoften necessary to actuate them. This tends to decrease productionthrough an increase of operator fatigue.

It is an object of this invention to provide an easily actuated gasoperated stapler which needs no compressor, external motor, electricity,or any Wires, gauges, tanks, or installation area. The stapler of thepresent invention is easy to operate and requires no externalconnections or apparatus. The motive force for the stapler is providedby interchangeable compressed carbon dioxide capsules.

Other objects and features of this invention will become apparent fromthe following drawings and description.

FIGURE 1 is a side view of the stapler partially in section to show theoperating parts;

FIGURE 2 is a side view of the trigger;

FIGURE 3 is a side view of the ram;

FIGURE 4 is a front view of the ram;

FIGURE 5 is a front view of the staple driver; and

FIGURE 6 is a top View of the first valve member.

The stapler is made up of two precision die cast aluminum halves thatwhen suitably joined form the body. The body 5 comprises a verticalcolumnar portion containing the operating elements to be describedhereinafter, and a lower laterally extending portion forming a staplemagazine. An .aluminum plate 53 spot welded to the columnar portion ofthe body and to the lateral end of the magazine forming portion bracesthe magazine. The upper edge of plate 53 near the magazine has a notch52 to receive the end of a staple follower rod 49 which extends into astaple passage 54 in the magazine portion. The rod 49 carries a fixedwasher 50 against which the rear end of follower spring 48 bears. Theforward end of spring 48 bears against staple follower 47 to resilientlyurge the follower against a stick of staples 40 in the passage 54. Therod 49 extends through a hole 51 in a rear flange of the follower toguide the follower. The magazine is loaded by unhooking the end of rod49 from the notch 52 and sliding the rod, spring, and followerrearwardly out of the magazine. A new stick of staples is inserted, therod, spring, and follower are replaced, and the end of the rod is hookedin the notch 52.

The upper end of the columnar portion of the body 5 has a rearwardlydirected threaded opening 4 to receive a compressed carbon dioxidecapsule 1. The capsule 1 has .a threaded projection 3 with a seal 7 atouter end thereof. Projecting rearwardly in the center of opening 4 isthe closed pointed end 6 of gas passage tube 10. The end 6 of the tubehas an inlet port 9 to admit gas into the tube. The capsule 1 is screwedinto opening 4 and pointed end 6 ruptures seal 7 to admit compressed gasthrough port 9 into tube 10. Suitable gas seals such as 2 and 8 areinserted at appropriate places between the capsule and the body.

The compressed carbon dioxide capsule 1 may be of the disposable type,or it may be of the type which may be recharged for subsequent use. Therecharging may ice be done from a larger portable container of highpressure gas, or it may be done from a gas compressor directly. Thepressure of the gas in the capsule and the volume of the capsule are notcritical, but preferably should be selected to provide more than thirtyoperations from a single capsule charge. While carbon dioxide has beenspecifically mentioned it is obvious that any equivalent gas could beutilized.

On the rear face of the columnar portion of the body 5 a trigger 15 ispivotally mounted. A pivot hole 16 in the trigger receives a pintle onthe body. Spring 17, compressed between spring guides 18 and 19 on thetrigger and body respectively, urges the trigger in a counter-clockwisedirection. The trigger has two radially extending arms, one having ahole 25 to receive a push rod 26 as will be explained, and the secondhaving a slot 20 which receives the locking flange 22 on the outer endof connecting rod 21. The rod 21 extends rearwardly from a sliding valvebody 24. The valve body 24 slides horizontally in a cylindricalrearwardly opening passage 23 in the body 5. The valve body 24 has avertically extending passage 12 that in the rest position of the valvebody is aligned with gas passages 11 and 13 above and below the valvebody respectively. The lower end of gas passage tube 10 opens into theupper passage 11. Thus it is seen that in rest position gas pressure isavailable in gas passage 13 below the valve. When the trigger ispressed, valve body 12 will be moved rearwardly by the lower arm on thetrigger and connecting rod 21, so that passage 12 is out of alignmentwith passage 11 and gas pressure is not available in passage 13.

Passage 13 opens into a charge chamber 14 and gas passage 33 leads fromthe lower portion of the chamber to a tube 34. In the opening fromchamber 14 to passage 33 is a valve 32 having a depending rod. The rodis connected to an arm 29, pivoted at 30 to the body 5. A spring 31surrounds the rod and urges the valve 32 to a normally closed position.The other end 28 of the arm 29 is connected to the lower end ofpreviously mentioned push rod 26. Push rod 26 carries a stop 27positioned so that a lost motion connection is formed between the radialarm of the trigger and the push rod 26.

The tube 34 extends vertically into a cylindrical chamber 37.Reciprocably slidable in the chamber 37 is a staple driving ram 36. Theram 36 has a top opening vertically extending bore 35 whichtelescopically receives the lower portion of tube 34. Extendingforwardly from bore 35 is a horizontaly extending gas escape bore 42,which when the ram is depressed registers with a port 43 in the forwardwall of the body 5. The ram 36 is resiliently urged to a normal upperposition by a spring 44 seated on the spring guides 45 and 46 on the ramand body respectively. The front face of the ram has a T slot formedtherein to removably receive the upper end 39 of staple driver 38. Thedriver 38 reciprocates vertically in a staple driveway 41, to drive theforemost staple of the stick of staples in the magazine.

The operation of the device is as follows. Assuming the magazine hasbeen loaded with staples as herein described, and a charged carbondioxide capsule has been attached to the body so that the seal is brokenand gas pressure is in tube 10. In the rest position of the device asillustrated in FIGURE 1, gas under pressure flows through tube 10,passage 11, valve passage 12, passage 13, and into chamber 14. Valve .32is closed to preclude gas flow into passage 33. Using the capsule 1 as ahandle the index finger of the operator pulls the trigger. Initialmovement of the trigger causes valve 24 to move rearwardly and thusclose off and seal the gas in chamber 14. Valve 32 remains closed due tothe lost motion connection between the trigger and the valve, thustrapping a metered charge of gas in chamber 14. Further movement of thetrigger results in an arm of the trigger engaging stop 27 to depress rod26 and thus open valve 32. The compressed gas in chamber 14 expands intotube 34 and bore 35 in the ram to drive the ram downwardly. Driver 38 onthe ram engages and drives the first staple in the magazine. When escapebore 42 in the ram reaches the port 43, the gas is vented to atmosphereand spring 44 returns the ram to rest position. When the trigger isreleased valve 32 closes and valve 24 opens so that a new charge ofcompressed gas enters chamber 14 and the device is ready for anotherstapling operation.

Various changes may be made in the details of constnuction withoutdeparting from the spirit and scope of the invention as defined by theappended claims- 1. A fluid actuated stapler comprising a reciprocabledriving ram carrying a driver blade, a gas chamber, a supply source ofcompressed fluid, a first fluid passage between said chamber and saidram, means to meter a 20 charge of compressed fluid to move the ram in astaple driving stroke, means to return the ram, and manually operatedmeans to actuate said metering means.

2. The stapler of claim 1, wherein the metering means comprises a firstvalve between said first passage and said chamber, and a second valvebetween said chamber and said second passage. I

3. .The stapler of claim 2; wherein said manually operated means is atrigger having a direct connection to said first valve and a lost motionconnection to said second valve.

4. The stapler of claim 3, wherein said supply source of compressedfluid is a detachable compressed gas capsule.

5. The stapler of claim 4, wherein said supply of compressed fl-uid is adetachable compressed gas capsule.

References Cited in the file of this patent Great Britain Aug. 31, 1948ave,

